1. Field of the Invention
The present invention relates to disk drives. More particularly, the present invention relates to an external disk drive compatible with a Serial Advanced Technology Attachment (SATA) standard including a SATA compatible shielded cable capable of receiving power signals from a host.
2. Description of the Prior Art and Related Information
Today, computers are routinely used both at work and in the home. Computers advantageously enable file sharing, the creation of electronic documents, the use of application specific software, and electronic commerce through the Internet and other computer networks. Typically, each host computer has a storage peripheral. For example, the most common type of storage peripheral is a rotating media storage device (RMSD), such as a disk drive (e.g. hard disk, 3.5 inch disk, CD ROM, ZIP, etc.). Further, it is becoming increasingly common to utilize external disk drives that are easily removable from a host computer such that data can be readily transferred from one host computer to another. For example, it is useful for people to have an external disk drive, which they can use at work to store work related projects, easily remove and take home with them, and then plug into their home computer such that they can work on their projects at home. However, it should be appreciated that external disk drives may either be fixed or removable.
Disk drives are typically connected to a host computer through a host interface connector for the transfer of commands, status and data. The host computer accesses the disk drive and reads data from the disk drive and/or saves data to the disk drive. The disk drive is typically connected to the host computer via a cable and a cable connector that connects to a device connector of the disk drive. For compatibility, the connectors and interface protocol are standardized. Accordingly, the cable, cable connector, and device connector should comply with the same interface standard. There are several disk drive interface standards, e.g., Advanced Technology Attachment (ATA) and Small Computer System Interface (SCSI) that have become common in the last decade.
However, disk drives are now being designed to comply with a newer standard, generally referred to as the Serial Advanced Technology Attachment (SATA) standard, which is the standard presently favored for newer computers. The SATA standard is being promulgated by the Serial ATA Working Group and is specifically referred to as the Serial ATA: High Speed Serialized AT Attachment specification or Serial ATA standard 1.0. The SATA specification defines various general standards for SATA compatible cable connectors, SATA compatible cables, and SATA compatible device connectors.
The SATA device connector defined in the SATA specification basically specifies a male robust type connector having an insulated housing, a first blade connector for supporting an electrical contact arrangement configured for data signals, a second blade connector for supporting an electrical contact arrangement configured for power signals, and two board locks fixed to the housing for attaching the device connector to a PCB. Further, the SATA device connector defined in the SATA specification sets forth that the housing includes a pair of opposed guide slots in each one of two opposite side walls of the housing that define a cable connector receiving area. The pair of opposed guide slots aid in guiding cable and back-plane connectors to mate with a blade connector. The SATA specification similarly describes a SATA cable connector that is a female robust type connector configured to mate with male robust SATA device connector.
Currently, external disk drives (e.g. ATA compatible disk drives), typically have built-in power supplies. There is considerable material cost for the power supply. However, in the case where the external disk drive is used with a host computer, the dedicated power supply is redundantxe2x80x94because the host computer most likely already has sufficient capability to provide the necessary power to the external disk drive. In addition, external powered disk drives require an additional alternating current (AC) power connection. In cases where the external disk drive is powered from a different source (i.e. another brand circuit) of power than the host computer, a ground loop may be set up, which could negatively impact the disk drive error rate or even signal integrity on the host interface.
The present invention relates to an external disk drive compatible with a Serial Advanced Technology Attachment (SATA) standard including a SATA compatible shielded cable capable of receiving power signals from a host.
In one aspect, the invention may be regarded as an external disk drive compatible with a SATA standard for attachment to a host having a conductive enclosure that includes a conductive back-panel. The external SATA compatible disk drive includes a disk for rotation within the disk drive, a moveable head for writing and reading data to and from the disk, a disk controller system for controlling operations of the disk drive, a printed circuit board (PCB) for mounting the disk controller system, a SATA device connector coupled to the PCB, and an enclosure surrounding the external SATA compatible disk drive. The external SATA compatible disk drive further includes a SATA compatible cable having a disk drive end that is coupled to the SATA device connector of the disk drive and a host end for of coupling to the host, wherein the SATA compatible cable is capable of delivering power signals to the external SATA compatible disk drive from the host. Also, the external SATA compatible disk drive includes a shield surrounding the SATA compatible cable. The shield is coupled to the enclosure of the disk drive.
In one embodiment, the enclosure surrounding the external SATA compatible disk drive is made from a conductive material. Further, the shield surrounding the SATA compatible cable is made from a conductive material. Particularly, the conductive shield surrounding the SATA compatible cable contacts and is electrically coupled to the conductive enclosure of the disk drive thereby forming a continuous electro-magnetic interference (EMI) shield about the external SATA compatible disk drive and the cable.
In a more detailed embodiment, the disk drive end of the SATA compatible cable may include a SATA cable connector to mate with a SATA device connector of the disk drive. The host end of the SATA compatible cable may also include a SATA cable connector. Further, the host may include a SATA host connector attachable to a slot of the conductive back-panel of the host. The SATA cable connector of the SATA compatible cable at the host end is capable of mating with the SATA host connector of the host such that SATA data signals and power signals are deliverable from the host to the external SATA compatible disk drive through the SATA compatible cable. The power signals from the host may be current limited.
In an even more detailed embodiment, when the SATA cable connector of the SATA compatible cable at the host end mates with the SATA host connector of the host, the conductive shield surrounding the SATA compatible cable is electrically coupled to the conductive back-panel of the conductive enclosure of the host. In this way, the SATA compatible cable is electrically coupled to both the conductive enclosure of the disk drive and the conductive enclosure of the host such that electromagnetic shielding is provided. Further, in another embodiment, the SATA host connector is attachable to the slot of the conductive back-panel of the conductive enclosure of the host by a conductive attachment shroud such that when the SATA cable connector of the SATA compatible cable at the host end mates with the SATA host connector of the host, the conductive shield surrounding the SATA compatible cable is electrically coupled to the attachment shroud. In this way, the SATA compatible cable is electrically coupled to both the conductive enclosure of the disk drive and the conductive enclosure of the host such that electromagnetic shielding is provided.
In a further detailed embodiment, the host may include a moveable cover to cover the SATA host connector. Also, as an example, in one embodiment, the SATA compatible cable may be compatible for use with a UL 1950/EN 60950 standard. Moreover, the SATA cable connector at the host end and the SATA cable connector at the disk drive end of the SATA compatible cable may also both the compatible for use with a UL 1950/EN 60950 standard.
In another aspect, the invention may be regarded as a system for connecting an external disk drive compatible with a SATA standard to a host, in which the host has a conductive enclosure including a conductive back-panel. The system includes an external SATA compatible disk drive having a SATA device connector, an enclosure surrounding the external SATA compatible disk drive, a SATA compatible cable having a disk drive end including a SATA cable connector that is coupled to the SATA device connector of the disk drive and a host end having a SATA cable connector that may be coupled to the host. Further, a shield surrounds the SATA compatible cable. The shield is coupled to the enclosure of the external SATA compatible disk drive. Additionally, a SATA host connector is attachable to a slot of the conductive back-panel of the host. The SATA cable connector of the SATA compatible cable at the host end may mate with the SATA host connector of the host such that SATA data signals and power signals may be delivered from the host to the external SATA compatible disk drive through the SATA compatible cable. In one embodiment, the power signals from the host may be current limited.
In one embodiment, the enclosure surrounding the external SATA compatible disk drive is made from a conductive material. Further, the shield surrounding the SATA compatible cable is made from a conductive material. Particularly, the conductive shield surrounding the SATA compatible cable contacts and is electrically coupled to the conductive enclosure of the disk drive thereby forming a continuous electro-magnetic interference (EMI) shield about the external SATA compatible disk drive and the cable.
In a more detailed embodiment, when the SATA cable connector of the SATA compatible cable at the host end mates with the SATA host connector of the host, the conductive shield surrounding the SATA compatible cable is electrically coupled to the conductive back-panel of the conductive enclosure of the host. In this way, the SATA compatible cable is electrically coupled to both the conductive enclosure of the disk drive and the conductive enclosure of the host such that electromagnetic shielding is provided. Further, in another embodiment, the SATA host connector is attachable to the slot of the conductive back-panel of the conductive enclosure of the host by a conductive attachment shroud such that when the SATA cable connector of the SATA compatible cable at the host end mates with the SATA host connector of the host, the conductive shield surrounding the SATA compatible cable is electrically coupled to the attachment shroud. In this way, the SATA compatible cable is electrically coupled to both the conductive enclosure of the disk drive and the conductive enclosure of the host such that electromagnetic shielding is provided.
In a further detailed embodiment, the host may include a moveable cover to cover the SATA host connector. Also, as an example, in one embodiment, the SATA compatible cable may be compatible for use with a UL 1950/EN 60950 standard. Moreover, the SATA cable connector at the host end and the SATA cable connector at the disk drive end of the SATA compatible cable may also both the compatible for use with a UL 1950/EN 60950 standard.
The foregoing and other features of the invention are described in detail below and set forth in the appended claims.